This application relates generally to gas turbine engines and, more particularly, to guide vane assemblies for gas turbine engines.
At least some known aircraft gas turbine engines include a compressor, a combustor, a turbine, and an augmentor. Airflow entering the compressor is compressed and directed to the combustor where it is mixed with fuel and ignited, producing hot combustion gases used to drive the turbine. As the performance demands of aircraft have increased, performance demands of the engines have also increased. For example, engines are being designed to transition between conventional take-off and landing (CTOL) operations, as well as, short-take and vertical landing (STOVL) operations. Augmentors are used in gas turbine engines to increase thrust as needed in a flight envelope and are located downstream from the turbine.
Augmentors include an inlet vane package that is upstream from a diffusing section of the augmentor. The inlet vane package includes a plurality of turning vanes that extend circumferentially within the engine and are used to facilitate aligning airflow directed towards the augmentor. Airflow discharged from the turbine may be distorted and turning the airflow, known as swing in swirl, with the inlet guide vanes may induce additional distortion into the airflow depending upon engine operation. Furthermore, depending on engine operation, an amount of swing in swirl required of the inlet guide vanes may increase beyond a capability of the guide vanes.
At least some known inlet guide vanes can tolerate up to approximately 30 degrees of swing in swirl before distortion losses caused by the inlet guide vanes may become harmful. However, as an engine transitions between CTOL and STOVL operations, an amount of swing in swirl required of inlet guide vanes may be greater than 30 degrees. More specifically, highly distorted flow induced during such engine transitions may actually become more distorted after exiting the inlet guide vanes and entering the diffusion portion of the augmentor. Such airflow distortion may cause low velocity wakes or flow separations which over time, may cause potentially harmful or costly flashback, auto-ignition, unpredicted engine performance losses, or even engine stability issues.
In one aspect of the invention, a vane assembly for a gas turbine engine is provided. The vane assembly includes at least one vane including a first body, a second body, and a passageway. The first body includes a first sidewall and a second sidewall connected at a leading edge. The passageway extends between the second body and the first body leading edge.
In another aspect, a method for operating a gas turbine engine is provided that facilitates improving performance of the engine. The engine includes an augmentor. The method includes directing airflow towards at least one vane assembly that is upstream from the augmentor and includes a vane first body, a vane second body, and a passageway extending therebetween, directing airflow into the vane assembly passageway, and discharging the airflow from the vane assembly passageway towards the augmentor.
In a further aspect, a gas turbine engine is provided. The engine includes an augmentor and a vane assembly. The vane assembly includes at least one vane that includes a first body portion, a second body portion, and a passageway. The first body portion includes a pair of sidewalls connected at a leading edge. The second body portion includes a first sidewall and a second sidewall connected at a leading edge. The passageway extends between the second body and the first body leading edge, and is configured to discharge air flowing therethrough towards the augmentor.